Tamperproof hinge



May 12 197D J. G. BALDWIN, SR 3,510,906

TAMPERPROOF HINGE Filed Feb. 16, 196e INV EN TOR United States Patent O 3,510,906 TAMPERPROOF HINGE James Granville Baldwin, Sr., 3605 S. Grady, Tampa, Fla. 33609 Filed Feb. 16, 1968, Ser. No. 705,990 Int. Cl. Ed 9/00 U.S. Cl. 16 128 4 Claims ABSTRACT OF THE DISCLOSURE A tamperproof hinge which prevents unauthorized removal of a closed door from its frame after the hinge pins have been Withdrawn. At least one hinge plate has a side edge bent to form a lip that extends across the side edge of the other hinge plate when the door is closed. The lip forms an abutment which engages the side edge of the other hinge plate to prevent sliding the hinge plates relative to each other when they are in face-to-face relation and the door is closed.

This -invention relates to tamperproof hinges and particularly to tamperproof hinges of the type in which a projection extends from one hinge plate and interengages with a portion of the other hinge plate to prevent unauthorized removal of a closed door merely by withdrawing the hinge pins.

There have been many attempts in the past to develop a fully effective tamperproof hinge wh-ich is also easy to install and inexpensive to manufacture. Those tamperproof hinges known in the past which are effective have, however, been quite expensive to manufacture, since the tamperproof features could not readily be incorported in a standard hinge by modifying the hinge. Thus, purchases of tamperproof hinges in the past have found the costs of these hinges to be prohibitive since they were specially made, and in addition, the prior tamperproof hinges were extremely diiiicult to install, since workmen were not familiar with the proper installation procedures for such h-inges.

Nevertheless, applicant has devised a fully eifective tamperproof hinge which can readilly be formed from an existing hinge, by modifying the hinge plates and, correspondingly, is quite inexpensive.

A significant feature of applicants invention is that the tamperproof characteristic of the hinge is attained by deforrning one side edge of one hinge plate to provide a lip that projects toward the other hinge plate, and cutting or recessing the other hinge plate so the lip projects across a side edge of this other hinge plate when the plates are -in face-to-face relation with each other. The lip then engages the side edge which it extends across when unauthorized removal of a door equipped with the hinge is attempted.

Correspondingly, an object of thi-s invention is a tamperproof hinge of unique construction.

Another object is a tamperproof hinge in which at least the side edge of one of the hinge plates is bent at a 90 angle to the body of the plate so it engages over a side edge of the other hinge plate when the plates are in face-to-face relation.

Another object in a tamperproof hinge in which one side edge of one hinge plate is bent at 90 to the body of the hinge plate and the side edge of the other hinge plate has a reces-s therein along its side edge into which the lip extends.

A further object is a hinge of the tamperproof type in which a lip projects from the side edges of each plate, one of the lips being formed on the upper portion of one plate and the other lip being formed on the lower portion of the other plate so the respective lips extend across the side edges of the respective plates.

A further and most signicant object is a hinge in accordance with the above-mentioned objects which is inexpensive to manufactre, is easy to install, and is fully effective.

Numerous other objects, features, and advantages of the hinge construction of this invention will become apparent with reference to the drawings, which form a part of this specification and in which:

FIG. 1 is an elevational view of a `first embodiment of the tamperproof hinge of this invention showing the hinge plate secured respectively to a door and door frame;

FIG. 2 Iis a view in section taken along lines 2 2 0f FIG. l;

FIG. 3 is a view corresponding to FIG. 2 but showing the position of the hinge parts when the door is closed;

FIG. 4 is an elevational view showing a second embodiment of the hinge of this invention;

FIG. 5 is a sectional view taken along lines 5 5 of FIG. 4;

FIG. 6 is a view corresponding to FIG. 5 but showing the position of the hinge parts when the door is closed;

FIG. 7 is an elevational view of a third embodiment of the hinge of this invention;

FIG. 8 is a sectional view taken along lines 8 8 of FIG. 7 and showing the position of the hinge parts when the door is closed;

FIG. 9 is a sectional view taken along lines 9 9' of FIG. 7 and showing the position of the hinge parts when the door is closed.

Referring now to the drawings in detail and particularly to FIGS. l-3, the iirst embodiment of the hinge of this invention will be described in detail.

Hinge 1 is comprised of a first hinge plate 2 and a second hinge plate 3. Each hinge plate is formed from flat metal of uniform thickness. Hinge plate 3 has bosses 4 and 5 integrally formed along one side edge, the bosses being spaced apart to receive bosses 6-8 integrally formed along the side of plate 2. Each of the bosses have aligned central openings of the same diameter which align with each other when the bosses are. interdigitated to the position shown at 1 so ahinge pin 9 can be inserted through the openingsto join the plates together for pivotal movement relative to each other. Customarily, a plug 10 is fitted into the opening in bottom boss 8 and is secured to the boss.

As will be apparent with reference to FIGS. l-3, hinge plate 2 is slightly wider than hinge plate 3. Projecting from hinge plate 2, at a angle to the body of the plate, is a lip 11 integrally formed from the material of the hinge plate and which extends along the entire side edge 12 of plate 1. Plate 3 has a straight side edge 13 which extends the length of this plate.

Hinge plate 2 is secured to door 16 by screws 17. Hinge plate 2 seats in a recess 18 formed in the side edge of the door. Hinge plate 3 is secured to door jamb 19 of door frame 20 by screws 21. Hinge plate 3 seats in a recess 22 formed in door jamb 19. As shown at FIG. 3, recess 22 of the door jamb is of the same width as recess 18 of the door. However, since hinge plate is is slightly narrower than hinge plate 2, a slot 23 defined by side edge 13 and end edge of the recess 22 extends along the side edge of hinge plate 3. When the door is closed, the lip on hinge plate 2 extends into this slot and across the side edge 13 of hinge plate 3. With reference to FIG. 3, it will be apparent that any attempted removal of the door, after the door is closed, after hinge pin 9 is removed will be defeated by the engagement of lip 11 with the side edge 13 of hinge plate 3. Thus, the lip positively prevents separation of the hinge when the hinge plates are in the face-to-face relationship shown at FIG. 3, the door being closed when the plates are in this position. Hinge plate 2 is advantageously connected to the door rather than the door jamb so that attempted separation of the hinge plates by sliding is effectively resisted by the side edge of hinge plate 3. It will be observed with reference to FIGS. 1 and 3 that the front surfaces 24 and 2S respectively of hinge plates 2 and 3 each lie in a plane which passes through the axis of hinge pin 9. Thus, faces 24 and 25 are in closely adjacent face-to-face relation lwhen door 16 is closed as shown at FIG. 3.

FIGS. 4-6 show a second embodiment of the tamperproof hinge of this invention. As shown at FIGS. 4-6, hinge 101 is comprised of a first hinge plate 102 and a second hinge plate 103. Hinge plate 103 has bosses 104 and 105 integrally formed along one side edge, the bosses being spaced apart to receive therebetween bosses 106- 108 integrally formed along the side of plate 102. A hinge pin 109 inserted through the opetnings of bosses 104-108, when aligned, joins plates 102 and 103 together for pivotal movement relative to each other. The usual plug 110 is fitted into the opening in bottom boss 108 and is secured to the boss.

In the embodiment of FIGS. 4-6 hinge plate 102 is the same width as hinge plate 103. Projecting from hinge plate 102 at a 90 angle to the body of the plate is a lip 111 integrally formed from the material of the hinge plate at side edge 112 of the plate. As is apparent with reference to FIG. 4, lip 111 has end edges 114 and 115 which are equidistantly spaced from the end edges 114 and 115 of hinge plate 102. The length of lip 111 as measured between end 114 and 115 is one-half the length of side edge 112. The distance from end edge 114 to end edge 114 is equal to one-half the length of lip 111 and correspondingly, the distance from end edge 11S to end edge 115 is equal to one-half the length of lip 111.

Hinge plate 103 has a side edge comprised of edges 113, 130 and 131. Edge 113 forms the bottom edge of a recess 136 formed in the side of hinge plate 103. The length of side edge 113 as measured between end edges 132nr`1d 133 of the recess is slightly greater than the length of lip 111.

Hinge plate 102 is secured to door 116 by screws 117. Hinge plate 102 seats in a recess 118 formed in the side edge of the door. Hinge plate 103 is secured to door jamb 119 of door frame 120 by screws 121. Hinge plate 103 seats in a recess 122 formed in door jamb 119. As shown at FIGS, 4-6, recess 118 is the same width as recess 122. Thus, edges 130 and 131 abut against edge 134 of recess 122. Likewise, side edge 112 of hinge plate 102 abuts against edge 135 of recess 118.

Edges 11e, 132, 134, and 133 define a slot into which lip 111 extends when door 116 is closed as shown at FIG. 6. The axis of hinge pin 109 lies in the plane of front faces 124 and 125 respectively of the hinge plates 102 and 103. Thus, when the door is closed as shown at FIG. 6 faces 124 and 125 are in closely adjacent facing relationship to each other, and lip 111 extends into slot 136.

With the door so closed, lip 111 extends across the side edge 113 of hinge plate 103. Thus, in the attempted removal of the door, after the door is closed, by withdrawing hinge pin 109 will be defeated by engagement of lip 111 with the side edge 113 of hinge plate 103. It will again be observed that hinge plate 102 is advantageously connected to the door rather than the door jamb so that attempted separation of the hinge plates by sliding is effectively resisted by the edge 113 of hinge plate 103.

FIGS. 7-9 show a third embodiment of the tamperproof hinge of this invention. Hinge 201 is comprised of a first hinge plate 202 and a second hinge plate 203. Bosses 204 and 205 are formed integral with hinge plate 203, and bosses 206-208 are formed integral with hinge plate 202. These bosses receive a hinge pin 209 which jolns the hinge plates together for pivotal movement about the axis of the hinge pin. The usual plug 210 projects into bottom boss 208 and is secured to the boss. Bent at an angle of to the plane of plate 202 is a lip 211. Llp 211 is located at side 212 of plate 202 and extends from top edge 230 of the plate downwardly a distance slightly less than one-half the length of the plate to terminate at an end edge 232. The portion of hinge plate 202 immediately beneath lip 211 is cut away along a straight side edge 231 spaced from edge 212 by a distance slightly exceeding the thickness of lip 211.

Hinge plate 203 has a lip 211 formed at side edge 213. Immediately above lip 211' the hinge plate is cut away along side edge 233. Lip 211 has a length as measured from end edge 234 of the lip to end edge 235 of the plate which is slightly less than one-half the length of the hinge plate. Thus, the side edge 233 has a length slightly greater than the length of lip 211.

Hinge plate 202 seats in a recess 218 formed in the side edge of door 216 and is secured to the door with screws 217. The recess is generally rectangular and has a side edge 236.

Similarly, hinge plate 203 seats in rectangular recess 222 in door jamb 219 and is secured to the door jamb by screws 221. The recess has a straight side edge 237.

As shown at FIG. 8, the slot defined between side edge 233 of hinge plate 203 and side edge 237 of recess 222 receives lip 211 when door 216 is closed and front faces 224 and 225 of the respective hinge plates are in face to face relationship with each other. Similarly, lip 211 is received in the slot 238 defined between side edge 236 of recess 218 and side edge 231 of hinge plate 202.

With reference to FIG. 8, it will be apparent that any attempted removal of the door after the door is closed, by withdrawing hinge pin 209 will be defeated by the er1- gagement of lip 211 with side edge 233 of hinge plate 203. Thus, lip 211 positively prevents separation of the hinge when the hinge plates are in the face-to-face relationship shown at FIG. 8.

With reference to FIG. 9, it will be observed that lip 211 engages in the slot defined between side edge 231 of hinge plate 202 and side edge 236 of recess 218. However, it will be noted that if door 216 is moved to the left lip 211 will engage side edge 236 of the recess to prevent such movement. Since doors, such as door 216 are usually constructed from wood, the narrow strip between edge 236 of the recess and face 238 of the door could conceivably be broken away by prying on the door in an attempt to remove it. However, since lip 211 (FIG. 8) engages the side edge 233 of metal hinge plate 202, removal of the door is thwarted.

The advantage of hinge 201 as shown at FIGS. 7-9 is that the hinge effectively prevents removal of door 216 when it is closed regardless of which hinge plate is connected to the door and which hinge plate is connected to the door jamb, since at least one metal edge will engage a lip to prevent sliding movement of the hinge plates relative to each other when the plates are in face-to-face relation as shown at FIG. 8.

Since the commonly available hinges have sufficient width that portions of the hinges can be cut away as shown at FIGS. l-9 without impairing the strength of the hinges, all the modifications shown in the drawings can be readily made from a hinge which is commercially available. Thus, the several embodiments of hinges shown and described herein can be formed from existing hinges merely by shearing away desired areas of the hinges and by bending the required lip for a particular embodiment.

While sever-al preferred embodiments of the tamperproof hinge of this invention have been shown and described herein it is to be understood that the scope of the invention is not limited to the specific embodiments disclosed and described.

What is claimed is: 1. A tamperproof hinge comprising iirst and second hinge plates separably connected by a removable hinge pin pivotally connectingthe plates together along one side edge of the plates; said iirst hinge plate comprising .a generally rectangular flat first body portion of uniform thickness and having rst and second side edges,

means defining aligned hinge pin receiving openings along said tirst side edge' of said body portion,

a lip integral with said body portion and extending from saidsecond side edge of said body portion toward said second hinge plate at an angle of approximately 90 to the plane of the body portion, said lip having a thickness essentially the same as said body portion and a length substantially less than the length of said body portion;

said second hinge plate comprising a generally rectangular tlat second body portion of uniform thickness and of the same size as said first body portion, and having first and second side edges,

means defining aligned hinge pin receiving openings along said irst side edge of said second body portion,

said second body portion having a recess at said second side edge, said recess presenting a bottom edge and an end edge, said bottom edge being parallel with and spaced inwardly of said second side edge by a distance approximating the thickness of said lip, said end edge connecting 'said bottom edge and said second side edge, and said bottom edge and recess having a length only slightly greater than the length of said lip;

said hinge pin connecting said plates for pivotal movement to a closed position in which said body portions are in face-to-face abutting relation,

said lip projects into said recess and extends across said bottom edge, and

a side edge of said lip lies closely adjacent said end edge of said recess;

said lip and said recess cooperating, with said hinge in said closed position, to prevent unauthorized removal of a door secured to one hinge plate, from a door jamb secured to the other hinge plate, by removing 4said hinge pin.

2. A tamperproof hinge according to claim 1 wherein said lip is located centrally along the second side edge of said rst Abody portion;

said recess is located centrally along said second side edge of said second body portion; and

said recess ypresents a second end edge facing toward said rst mentioned end edge of said recess and spaced therefrom -by a distance only slightly greater than the length of said lip.

3. A tamperproof hinge according to claim 2 wherein said lip and recess are each of a length approximately equal to one-half the length of one of said second side edges.

4. A tamperproof hinge according to claim 1 wherein said lip is ofset toward and extends to one end edge of said irst body and has a length approximately equal to one-half the length of one of said second side edges;

said recess is offset toward and terminates at that end edge of the second body which is adjacent said one end edge of the first body, said recess having a length yapproximately equal to one-half the length of one of said second side edges;

said rst body includes a second L-shaped recess identical to said lirst mentioned recess and extending from said lip to the end edge of the rst body opposite from said one end edge;

said second body includes a second lip identical to said first lip and extending along the second edge of said second body, from said recess to the opposite end edge of the second body;

whereby, said rst and second body portions are identical, and with said hinge plates closed, said lip enters said recess and said second lip enters said second recess.

References Cited UNITED STATES PATENTS 1,676,541 7/ 1928 Friedman 16-137 1,105,666 8/1914 Johnson 16-137 2,058,341 10/1936 Mink 16-128 BoBBY R. GAY, Primary Examiner D. L. TROUTMAN, Assistant Examiner 

